What was the outcome of the Wabash v. Illinois case regarding states' rights?

The outcome of the Wabash v. Illinois case in 1886 significantly clarified the boundaries of states' rights in relation to interstate commerce. The Supreme Court ruled that states do not have the authority to regulate interstate commerce; this responsibility lies solely with the federal government. This decision was pivotal because it established that any attempt by a state to impose its regulations on interstate commerce would be unconstitutional.

Wabash v. Illinois arose from a dispute where the state of Illinois attempted to regulate the shipping rates of railroads that operated across state lines. The Supreme Court determined that such regulations interfered with interstate commerce, which the Constitution grants Congress the power to regulate. This ruling effectively limited the ability of individual states to control or influence aspects of commerce that cross state boundaries, reinforcing the idea of a unified national market and the federal government's role in regulating trade.